> ## Documentation Index > Fetch the complete documentation index at: https://docs.defindex.io/llms.txt > Use this file to discover all available pages before exploring further. # General/FAQ ### What is DeFindex? Yield infrastructure for wallets and fintechs. See [What is DeFindex](/defindex-protocol/what-is-defindex). ### How does it work? A vault holds user deposits and allocates them to strategies, and each strategy connects to one external yield source. [Understanding DeFindex](/getting-started/index) sets out the layers and who controls each. ### How does a partner make money? By setting a fee on the yield the vault generates, never on the deposited capital, up to 90%. See [Partner Fees](/getting-started/partner-fees). ### Is it secure? The contracts are open source and audited, and the guarantees are enforced in the contract: strategies are whitelisted at creation, funds cannot leave the vault's ecosystem, and no role can freeze a withdrawal. See [Risks and Audits](/security/risks-and-audits). ### Can a vault's strategies be changed after it is created? Not by any vault function: the assets and strategies are fixed when the vault is created, and there is no function to add or swap one afterwards. The one path that can change them is a contract upgrade. A vault deployed as upgradable lets its Manager replace the whole contract code; a vault deployed with upgradability disabled makes the list permanent.